The Buzz Surrounding Spinal Surgery: Electricity and Other Techniques Help with Healing
Surgery to join vertebrae in the spine doesn't always work. In some cases, the bone graft placed between the vertebrae may not unite, or the graft simply may not be strong enough. Doctors use the term "nonunion" to describe a failed fusion.
Certain risk factors, like being overweight or smoking, can make fusion less likely. So can taking anti-inflammatory drugs or steroids right after surgery. Still, doctors want to get good results for all their patients. In this article, the authors review techniques that may help the spine heal after surgery.
Whether or not the fusion takes has a lot to do with what happens during surgery. Implanting metal hardware such as screws, plates, or rods to reduce spinal movement after surgery has improved the success of spinal fusion. Also, the greater the blood supply, the better the healing. Surgeons can improve blood supply by clearing damaged tissues out of the way and by taking extra care around healthy tissues. With an improved blood supply, the fusion site gets more of the oxygen and infection-fighting cells that promote healing.
After surgery, electrical stimulation may also help improve fusion success. A version of this technique was first used in the 1950s to promote bone growth. Surgeons implant an electrode that gives a mild current directly to the fusion site. Or electricity can come from wearing a pulsing device on the skin up to 24 hours a day.
Electrical stimulation has worked wonders on fusion rates. High-risk patients have better chances of spinal fusion with this technique. (These patients include those who smoke or are overweight, and those who have surgery at multiple levels of the spine.)
Ultrasound therapy is another possibility for improving fusion rates. This technique has recently been tested on rabbits. A low-intensity ultrasound wave may help spinal fusion. Like electrical techniques, this one can be done at home, and it may take only 20 minutes a day.
Scientists have begun using gene therapy to develop growth factors. These are natural proteins found in the body that encourage the growth of healthy bone. Doctors are excited about the recently discovered bone morphogenic proteins (BMPs). These proteins have shown promising results in growing and fusing bone tissue.
Most of the techniques mentioned here are new to spinal fusion. There is still a lot of research to be done. But in general, these methods promise better results for spinal fusion surgery.
Jason C. Eck, MS, et al. Techniques for Stimulating Spinal Fusion: Efficacy of Electricity, Ultrasound, and Biologic Factors in Achieving Fusion. In The American Journal of Orthopedics. July 2001. Vol. 30. No. 7. Pp. 535-541.